Impact-tool.



C. B. RICHARDS.

IMPACT TOOL.

APPLICATION FILED Nov. so, 1906.

l Patented Nov. 94, 1908.

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vUNITED STATESMPATENT OFFCE (JlLRLlIS B. RlUHARDS, Ol" CLEVELAND, OHIO, AiSs'ltlNtlR .lO CLEVELAND PNEUMATIC TUUU QQLI'Y, OF CLEVELAND, OlillO, A COP PORATLON Oli OHIO.

IMPACT-TOOL.

Specification of Letters Patent.

Patented Nov. 2.4, 1908.

Application filed November 30. 1905. Serial No. 3&5/193.

.To nl! whom lit may concern.'

Be it known that I, CHARLES B. Rioniinns. a Citizen of the llnited States, resident ol- Cleveland,.ronnty of Cuyahoga and State f, contemplated applying that principle, so as to distinguish it from other inventions.

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The annexed drawings and the following description set forth in detail, one mechanical forni embodying the invention; Suchdetail construction being but one of various inerhanical 'forms in which the principle of the invention may be used.

In said annexed drawings Figure I represents an axial Aseetion of my improved irn part tool, showing the valve in' position to control the motive fluid to beadmitted to the rear or up er end of the Working cylinder to throw t e plunger forward, and Fig. ll, an axial section of the tool with a portion of the handle broken away and removed, and showingf the valve in position to oo ntrol the motive linid to admit the same at the forward or lower end of the working cylinder to throw the plunger rearward or u ward.

The tool has a working-c linder or arrel, l. within the'cylindrieal lbore of which n plunger, 2, reoiproeates. The front or lower end of this barrel is formed with a toolsotket 3, into which the shank, 4, of the working-tool is inserted. This latter tool may be a chisel, a 'calking tool, a rivet set or whatever other :form 'ofl toolmay be required for the work to be done. The rear or um end of the barrel is threaded and is screwed into the outer end of a socket, 5, which outer end. is internally threaded and longitudinally slitted so' as to be lirnilv damped upon the serewthreaded end ot' the barrel by means of a clamping-bolt., 6. Said smvketiornis a )nrt of the handle, T, upon whit-h is tortue a throttle-valve casing7 S. having an internally serewthreaded soi-kel'. i). into whieh the nipple of a hose through which the motive fluid is supplied inny be. screwed. An inlet passage, l0, is Formed through the side of the handle hnving the valve-easing, through which latter this passage connect-s with the inlet-nipple, and a 'tliroitle-.'alve, l1., connected to be aetuated by a suitable trigger. nivoted .in

the handle, eontrols the passage. through the valve-easing and is held normally closed by a suitable spring, 13. An annular groove r channel. ll,n is foi-ined in the bottoni of the handle-socket and connnunioates with the inlet-channel and forms a part thereof.

A valve-bloelt l5, is clamped between the rear or upper end oi' (he barrel and the bottoni of the handle-socket, and said valve *bloeit has an axial valverlnnnber formed with a uinnber of annular grooves 'or ports,

vwhich will hereinafter be more fully described. An annular inlet groove or port, 1G, lis formed in the valve-chamber near its rear or upper end, aud eonnnunieates `with the annular'inlet-channel l-l through a series ot holes l?. A series of right-an led passages 18;"'extend from the bottoni o' this annular port lo :mdrepen into the sides of the vahf'e-ehainber, n1 'S'ihort distance below the port. An annular distributing groove or port 19, is formed in the interior ot' the vnlve'whainber inimedintely below these right-'angled passages, and one orniore rightangled passages, 2t), extendfroin this port into a large longitudinal passano, 21, in the valve-blool which longitudina passage has a restricted opening, 22, through the lower or forward end of 'the valve-blocl This last-mentioned restricted opening communi oates with a riglitangledpassage, 23, in the rear or upper end ot the barrel, which passage opens from the end of the barrel und `into the bore ol the barrel near the rear or upper end. ein annular exhaust-port, 24, is .termed ,in the Side of the valve-chamber :i

short distance below the annular port 19, and` exhaust-ports, 25, are formed through the sides oit' the valve-block from this annular port end open :into an annular exhaust-space, 26, formed between the valve-block and the interior of 'the handle-soltet. Said exhaustspace communicates w th the outer air through one or more exhaust-ports, f2?, in the socket. An annular nistonfohaniber 28, of proportionally considerable length or width is formed in the interior of the valve-chainber below the annular exhaust-port Qfl. rlhe u1 per end of this piston-chamber communientes by means oi' :i passiwe, 29, with the longitudinal passage 21.

by means ot an oblique passage, 30, opening through the lower end the valve-block,

with a longitudinal bore,'3l, in the side of p Tllie lower end ot' 'the annular )retort-chamber communicates llt) permanent exhaust from the lower end of the annular chamber. A bore, 36, is formed through the sides of the valve-block and the barrel and extends :troni the upper live-air groove or port lo to a point at about the 'middle of the working-cylinder, registering with the port 32 which hasV communication to the lower end ot' the annular piston-chamber 28 in the valve-chamber. A longitudinal' bore, 37, is formed through the side of the valve-blfwk and barrel and extends from the vannular distributing-groove or-port 19 to the lower end of the working-cylinder. A longitudinal bore, 38, is formed through the side of the valve-block and the barrel and extends from thelower'exhaust-port 33 to near the lower `end of the working-'cylinder so as to form a permanent exhaust from the lower portion of the working-cylinder. A hollow valve, 39, has play in the valve-chamber and has at its upper end a piston, 40, which has play over the annular inlet-port l'so as to cover the same when the valve is in its upper position and to uncover the 'same when thef valve is in its lower position, and so as to cover the rightangled passages 18 when the valve is in such position. f -Y A step or shoulder, 41,'is formed upon the valve so as to have bearing against the partition 42, which separates the annular distributing port 19 from the annular exhaustport 24: when the valve is in its upperposition. A piston, 43, is formed upon the valve 2o have play in the annular piston chamber 28, and the lower end of the valve has play over the annular exhaust-port 33 so, as tol cover the same when the valve is in its lower position andto 'uncover the same when the valve is inlits upper position. The plunger 2 has an vannular groove, 14, near its upper end soA as to register with the port 32 and lower end of the bore 36, so as to place these two ports and their bores in communication when the plunger is at the extreme of its forward or down stroke.` The two endsl of the valve have the same pressure area, so that the valve is balancedviin its chamber. ln the drawings, the axial bore o' the valve is ag end, but the combined areas of the lower end of the valve and ofthe shoulder within the bore .of the valve equal the area of the upper ond or' the valve. By the formation of the lmvfer atv the lower end than 'at the upper f soave-2.-

ldle than at the ends, so thatthe upper pressure area of the large valve-piston 43 is less i than the lower pressure area of the same.

vThe valve-block is made in two pieces for the purpose of permitting the large valvepiston to be fitted into the large annular y piston-chamber,'butthe two pieces form one Valve block. formed around thevalve be piston of the latter and the stepped '01 shouldered portion so that, when the valve is in its lower position, it may connect the distributing-port 19 with the exhaust-port 24-and, when the valve 'is in its upper position, it may connect the right-angled pas- A11 annularchannel, 45 fis Ween the upper sages 18 with the annular distributing-port I 19 and right-angled passage20.

-When the tool is to be put in operation, the inlet-socket 9 is coupled to a hose -or other flexible connection with. the supply of Imotive iuid,-compressed air being usually the motive fluid. The working tool is placed against the work to be acted. upon,- the operator grasping the tool by the handle and forcing the latter against the work. The throttle-valve is 'now opened so as to admit air into the tool, which will cause the piston to reciprocate and-deliver rapid blows upon'the shank of the working-tool. This operation is accomplished in thefollowing manner: We will assume that the parts of ,the tool are in the positions shown in Fig. I,

in which the valve is shown in its lowermost position and the -piston is shown in its uppermost position. lThe air will passfrointhe inlet passage in the handle, throughther` annular series of`holes in thevupper Aend ofi'f the valve-block into the upper annular inlet-1- port, which is uncovered by the valve, and thence through the hollow Valve into the upper portion of the working-Catlin r,.l

where it will drive the plunger downw rd todeliver its blow uponA the shank oifl thel lit workingtool. While the plunger istie-'A scending, air below .the same is forced youtof the lower end of the working-cylinderv by- Y the descending plunger through the -pemaf nent exhaust-passage 38 to the lowerann'ula`.l"

exhaust-portand out to the atmosphere, and

also through the distributing passages? to; the annular distributing-port 119 which com-l j l municate's with the upper exlgiaust-y ort; 24,".f'

whence theexhaustin' air passes ou .tof/the 11,2 atmosphere. Then tie plungep` 'arrivesg-f'at the lower extreme' of its stroke, the,1a11'nular-4 ward. The air above the valve-pistonifpasseu out through the port 29 in the u the piston-clianibcr and through the right-- angled passage Q() und distrihuting-port l to the upper exhaust-port 24. A lso, as thc lower area ot' the valve-lusten greater than the upper area of the same, the prcssiu'c trom below ruiclily ,)vcrcomes any lnick-presenrc from aiuove.` ll'hcn thc valve has arrived at its upper position, it has uncovered the lower exhaust-port in the valve-chamber and covered the upper inlet-port in the latter. Live-air will now pass throughl the rightangled passages 1S to the annular port tu, whence it will pass down through the here or passage 3T to the lower end of the working-cylindex", driving the plunger upward. The air behind the plunger will freely cxhaust through the lower exhaust-port and out to the atmosphere. The upper exhaustport in the valvechamber is closed by thcshouldered portion. of the valve. Live air will also pass from the annular distributingptrrt lt) through the right-angled passag(` 2() and 2l. and thence through the restrictedvopening 22 and passage 23 into the upper end ot' the cylinder, all as will appear hy reference to' Fig'. Il. As Vsoon as the plunger irrives at the extreme of its vupstroke, itwill close this right-angled,passage 23 and so 'that' ,E39 into confine the live-air in the passage 2l, said air will pass through the port lthe annular piston-chamber, to act vga-inst' Vthe upper side ot the large valvcniston, while live-air in the distributingihort 19 also acts against the step or shoulder f the valve, thereby forcing the val ve down,

s that the parts will occupy the position slliown in F 1g. l, when the operation Vwill again be repeated. i

.is the rightanglcd passage which contrdls the forward ordownward movement of .the valve is located some distance from the rear or upper end of the cylinder, said passage will be closed by the returning plunger' short-ly before the latter arrives at the enfl ol its stroke and the valve will be shifted hctorc -the plunger strikes Ithe valvc-blocl, so as to close the rear-end exhaust and open the inlet to admit. air into the cylinder to cushion the plunger and drive the Same forward.- The action of this tool is very rapid, as the connection of the two ports at the middle of the cylinder by the groove in the plunger will be immediately followed by shift ing upvard of the valve and return of the plunger, andthe closingr by the plunger off the rightangled control ing passage at. the upper end yof the cylinder will immediately produce forward or downward movement of the valve and cushioning and forward or downward movement of the plunger. By this movement ol" the valve in a direction opposite to that of the plunger and before the lattcr'vreaches the extreme of its return stroke, all yar or shock by Athe returning plunger pper cud ot' v is avoided.

A lniy making the i valve hollow or m .thc t'orm ol' a .shell-valve, the valvimay he made of'proportionally. considerable diameter. so usto have a large wearing surface. und at the same time bc of comparatively light weight so as to he easily moved.

the iulctair passes through thc hollow interior oi' the valve and directly into the cylinder. the air will tlow into the cylinder in a large and unobstructed volume to drive thc plunger forward or dowinvard. The exhaust from therear or upper en d ot the cylinder docs not flow through thc valve but. directly out through the lower exhaust-port immediately above the rear or upper end ot' 1 the cylinder. By providing an individual 'exhaust foreach endof the cylinder, exhaust will take place freely and immediately upon shifting of the valve. There i's at all times a tlow of live-air into the passage 2l and acting against the upper face ot' the valvepiston. but the pressure of such air is less than the normal pressure and will notm'ovc the valve, owing to the fa'et that some air is escaping through the right-angled passage or the restricted passage It is only when the port is closed by the plunger aud exhaust is. thus cut ofi, that. there is t'ull normalpressure against thc upper face ol the valve-piston to movc the valve. This valve movement is equally well adapted for use in hammers in which the stroke :ot the plunger is longer than the plunger itself, or so-ealle'd long-stroke hammers 4as well as in hannners ot' the` type herein illustrated, in which thc stroke of the plunger is shorter than the plunger itself, or so-called shortstroke hammers. The only change required is in the plunger, which is made without the circumferential groove, and the barrel. in which the' bore 36 is dispensed with, as wcll as the permanent exhaust bore 38, in place ot' which holes throu h the sides of the barrel are provided. e valve-block and the valve arc of the same construction and in all respects identical in the two types of tool.

Other modes of 4applying the principle of my invention may be employed for the mode herein explained. Change may therefore be made asrregards the mechanism thus disclosed, provided thc principles of construction set forth respectively in the following claims are employed.

I therefore.particularly point out and. distinctly claim as my invention 1. In a pneumatic impact tool., .the oombiuation with a working-cylinder and a plunger reciprocable therein, of a val ve controlling the motive fluid. to reciprocate the plunger and consistingvof a hollow shell or cylinder having its end-areas equal to balance it and formed with a piston acted upon on alternate sides by motive fluid under normal prcssurecontrolled by the plunger.

2. In a pneumatic impact tool., thc combination of a working-cylinder, a plunger reciprocable therein, inlet and exhaust passages for the motive fluid, a valve 'movablel in a chamber .at one end of the' cylinder and 5 serving to control admission and exhaust of motive fluid to and from the cylinder, said valve having two pressure faces, a passage to one of said pressure faces and to a point inthencylinder where it maybe connected to the motive fluid supply when the plunger is at one end of its stroke, and a passage open to the'other pressureface and havin meansfor admitting and exhausting motive fluid' into and out of it and opening into the cylinder to be covered by the plunger when the latter is at the other end of its stroke.

8. ln a pneumatic impact tool, the combination of a working-cylinder, a plunger reciprocable therein, inlet and exhaust passages for-the motive'iiuid, a valve movablev in a chamber at one end of the cylinder and serving to control admission and exhaust of motive fluid Ato and from 'the cylinder and having its end-areas-eqnal to balance it, said g5 valve having a piston formed with two pressure faces, a passage. to 'one of said pressure faces and to a point in the cylinder' Where it may be connectedto the motive fluid suppl)Y when the-plunger is at one end of its stroke, and a passage open to the other pressure face and having means* for' admit,- ting and exhausting motive fluidl into and out of it and opening into the cylinder to .be Coifered by the plunger when the llatter is at the other end of its stroke. y

fl. In a pneumatic impact tool, 'the combination of a working-cylinder having-an inlet and exhaust port and passage leading from its forward end, a reciprocable plunger' 40 in such' cylinder, a valve-chamber in axial alinement with said cylinder and open to the l rear end of the same outside the path of travel of the plunger and formed with an `rinlet-port at its rear end and an exhaustport at its forward end andwith an exhaust- 4 port and an'inlet-port and aA distributing port between the same and communicating lwith the forward port and passage oflthe 4cylinder, a tubular valve reciprocable in the valve-chamber to alternately cover and untcover the end inlet and exhaust ports'with its ends and formed with pistons to alternately connect the end-port and passage vof the cylinder with the inlet and exhaust, and plunger-controlled means for reciprocating vthe valve.

5. 'In a pneumatic impact tool, the com- -bination of a working-cylinder having an 'inlet and exhaust port and passage leading from its forward end, a reciprocable plunger in such cylinder, a valve-chamber in axial -alinement with said cylinder and open to the rear end of the same outsidethe path of travel of the plunger and formed with an inlet port at its rear'end and an exhaust- 65 port .at its forward end and with another exlnnist-port, a tubular valve reciprocable in the valve-chamber to alternately cover and uncover the end inlet and exhaust ports jwith its ends and formed with pistons to alternately connect the end-port and passage "of the cylinder with theinlet and exhaust,

,and plunger-controlled means for recipro- Jcating the valve.

In testimony that I claim the foregoing to be my invention I have hereunto set my hand thisllth day of June, A. D. 1906.

CHARLES B. RICHARDS.

Witnesses:

C. Gnnvns, .l WM. SECHER.' 

